080
FXUS64 KMRX 182320
AFDMRX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MORRISTOWN TN
720 PM EDT TUE AUG 18 2026
..NEW AVIATION
KEY MESSAGES
UPDATED AT 711 PM EDT TUE AUG 18 2026
- DRY WEATHER CONTINUES THROUGH TOMORROW, THEN AN APPROACHING FRONT
WILL BRING SHOWERS AND STORMS ON THURSDAY AFTERNOON/EVENING, A FEW
OF WHICH COULD BE STRONG TO SEVERE. RAIN CHANCES CONTINUE INTO
FRIDAY WITH THE FRONTAL PASSAGE.
- MOSTLY DRY CONDITIONS WITH NEAR NORMAL TEMPERATURES THROUGH THE
WEEKEND AND EARLY NEXT WEEK
DISCUSSION
ISSUED AT 148 PM EDT TUE AUG 18 2026
TODAY HAS BEEN A WELCOME BREAK FROM THE HOT AND WET WEATHER OF THE
PAST SEVERAL DAYS, THANKS TO SURFACE HIGH PRESSURE SETTLING OVER THE
AREA AND A DRY W-NW FLOW THROUGH THE COLUMN. THIS PATTERN CONTINUES
THROUGH WEDNESDAY AS THE TRACK OF MCSS WILL BE ALONG AND NORTH OF
THE OH RIVER. ONE CONCERN FOR TONIGHT IS FOG DEVELOPMENT, WHICH
COULD BE DENSE AND EXTENSIVE IF LAMP GUIDANCE PANS OUT. OUR
TEMPERATURES HAVE BEEN A LITTLE COOLER TODAY, BUT DEWPOINTS ARE
STILL IN THE UPPER 60S TO MID 70S IN MOST SPOTS AND WILL LIKELY
REMAIN THERE TONIGHT. WITH THE SURFACE HIGH REMAINING OVER THE AREA
AND CLEAR SKIES, IT SEEMS LIKE A GOOD BET TO SEE WIDESPREAD DENSE
FOG IN THE EARLY MORNING.
ON THURSDAY, THE COLD FRONT THAT WILL BE THE FOCUS FOR SHOWER/STORMS
IN THE LOWER OH VALLEY ON WEDNESDAY WILL PUSH SOUTHEASTWARD IN
RESPONSE TO A DEEPENING TROUGH OVER THE EASTERN CONUS. THE TIMING OF
THIS FRONT REMAINS UNCERTAIN, WHICH WILL AFFECT HOW EXTENSIVE AND
INTENSE THE SHOWERS/STORMS WILL BE IN OUR AREA AHEAD OF IT. NAM
FORECAST SOUNDINGS SHOW PLENTY OF MLCAPE IN PLACE BY THE AFTERNOON,
3000-4000 J/KG, WITH DECENT LAPSE RATES UP TO 600 MB. THERE IS SOME
UNIDIRECTIONAL SHEAR AS WELL WITH THE MIDLEVEL FLOW AROUND 30-40 KT.
THIS SUGGESTS SOME POTENTIAL FOR DAMAGING WINDS, AND MAYBE SOME
HAIL, IF TIMING IS FAVORABLE. WE ARE NOT CURRENTLY IN THE DAY 3
OUTLOOK FOR SEVERE, BUT IF THE NAM'S DEPICTION HOLDS, THAT COULD
CHANGE. WITH THE UPPER TROUGH AXIS MOVING THROUGH AND THE SURFACE
FRONT POTENTIALLY SOMEWHERE NEAR THE AREA ON FRIDAY, THE CHANCE OF
SHOWERS WILL CONTINUE, MAINLY IN THE EASTERN HALF.
THE FRONT WILL BE EAST OF THE AREA ON SATURDAY, BRINGING A DRIER AIR
MASS TO THE AREA FOR THE WEEKEND. THE UPPER TROUGH WILL STILL BE
OVER THE AREA, SO A FEW SHOWERS CAN'T BE RULED OUT, BUT MOST OF THE
AREA SHOULD REMAIN DRY. A NW FLOW REMAINS IN PLACE THROUGH THE FIRST
HALF OF NEXT WEEK WITH THE STRONG RIDGE OVER THE SOUTHERN PLAINS AND
A TROUGH OVER THE EAST COAST, WHICH WILL FAVOR DRY CONDITIONS AND
NEAR NORMAL TEMPERATURES THROUGH THURSDAY.
AVIATION
(00Z TAFS)
ISSUED AT 711 PM EDT TUE AUG 18 2026
FOG IS LIKELY IN THE EARLY MORNING HOURS, MAINLY NEAR TRI AND
TYS. VFR CONDITIONS WILL RETURN SHORTLY AFTER SUNRISE. ANOTHER DRY
DAY IS EXPECTED TOMORROW AFTERNOON AND EVENING. LIGHT WINDS WILL
BE NORTHERLY.
PRELIMINARY POINT TEMPS/POPS
CHATTANOOGA AIRPORT, TN 69 95 72 94 / 0 0 20 30
KNOXVILLE MCGHEE TYSON AIRPORT, TN 68 91 70 91 / 0 0 20 20
OAK RIDGE, TN 66 90 70 89 / 0 0 30 40
TRI CITIES AIRPORT, TN 64 87 66 86 / 10 0 30 30
MRX WATCHES/WARNINGS/ADVISORIES
NC...NONE.
TN...NONE.
VA...NONE.
DISCUSSION...DGS
AVIATION...MCD
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